The only varnish that will effect the purpose of preservation is one that has oil as its basis.
All varnishes made from spirit leave on the wood a deposit of rosins of varying degrees of hardness.
These deposits, if soft, are soon worn away by the least friction and even if left untouched will, in time, disappear by the process of natural disintegration, and will leave the instrument itself bare and disfigured. Our attention must then be especially confined to oil varnishes.
In this varnish the opposite effect is obtained, the gums and rosins are dissolved in the oil and the whole forms a siccative substance which, to a considerable extent, assimilates to the superficial part of the instrument, and the oil gradually drying leaves the rest amalgamated with the wood which it covers, and yet at the same time forms a part of.
Although to act as a preservative is the chief function of varnish there are several other properties it must possess if it is to be perfect.
